Researchers help design incentive programs to rid South America of invasive beaver

January 11, 2016

Beaver imported decades ago from North America to Tierra del Fuego in South America now number over 100,000 and are causing significant ecological damage. Photo courtesy of Anna Santo.

BLACKSBURG — North American beavers have wiped out 30 percent of forests along rivers and streams in Tierra del Fuego, a remote archipelago at the southern tip of South America, causing the greatest landscape change to these fragile forests in the last 10,000 years.

It’s no surprise, then, that the governments of Chile and Argentina want the invasive beavers gone. But eradicating them has proven to be difficult, researchers found, because it requires the participation of every single landowner in the area.

“Payment programs help, but getting all landowners on board is the crux of this and many other invasive species eradication programs around the world, which is why we wanted to study landowner preferences in this far-flung island chain on the other side of the world,” said Michael Sorice, assistant professor of outdoor recreation and human dimensions in Virginia Tech’s College of Natural Resources and Environment.

The team’s research, published in the November issue of Global Environmental Change, found that landowners in Tierra del Fuego were willing to participate in a beaver removal program designed around the landowners’ unique interests. Specifically, participation increased under three conditions: increased payments, increased expectations of program success, and, surprisingly, low requirements for landowner involvement in the eradication efforts.

“Based on previous research about ranchers’ values, we expected landowners to express their desire to maintain their independence by hunting beavers themselves,” said Anna Santo, who earned her master’s degree in forestry at Virginia Tech in May 2015 and is lead author of the paper. “Instead, landowners preferred a program that would allow the program managers to have access and complete control over beaver eradication on private land.”

The 2014 study considered how the structure and design of an incentive program influence landowner participation. “Many payment programs for ecosystem services are created under the logical assumption that if you want to engage landowners in conservation, you just need to pay them,” said co-author Sorice, who studies the stewardship behavior of private landowners. “But that’s only part of the picture. Nonmonetary factors in program design matter but are often overlooked. The key is to evaluate the needs and preferences of the stakeholders you want to engage during the design phase of a conservation program.”

In 1946, the Argentine government introduced 20 North American beaver to create a fur industry; the mammals have expanded into Chile and now number over 100,000. While the United States is actively restoring the North American beaver in the Pacific Northwest, Chile and Argentina have signed a binational treaty to eradicate the species before its ecological impacts spread further, to the mainland and throughout the archipelago.

“Trees along rivers and streams have not co-evolved with beavers and require decades or even centuries to recover from their impact. This makes forest restoration very difficult ecologically,” said co-author Christopher Anderson, associate professor in the Institute for Polar Sciences, Environment, and Natural Resources at the National University of Tierra del Fuego and an adjunct faculty member at Virginia Tech.

“Humans introduced beaver to this fragile landscape and now humans must act together if important ecological resources are to be restored,” Sorice said.

Despite serious ecological impacts, cooperation from private landowners to eradicate beaver is not guaranteed. “Beaver are charismatic animals and are not perceived as a threat to several landowners in the area,” Santo explained.“In some cases they are even used to attract tourists. The problem is that a lack of support from a single landowner can delay or completely derail a conservation campaign to eradicate this invasive species.”

According to the authors, the study’s unexpected finding that landowners prefer a program that takes more control over beaver eradication on their land may be a result of economic setbacks (such as the decreased demand for Patagonian timber), tax increases, depredation of livestock by wild dogs, and a shortage of skilled ranch labor. “But the preference for passive cooperation could be an advantage from the perspective of the eradication program since it could allow for more consistent and widespread implementation,” Santo said.

The research suggests that identifying landowner preferences during the design phase of a conservation program can result in innovative agreements better adapted to the local context. “Payment programs for ecosystem services are about more than just payments,” Sorice said. “When they are codesigned with local stakeholders, they will achieve wider participation.”